PMI-SP Exam - Topic 3 Question 98 Discussion

According to the question, you have to use the estimating technique that has a higher

degree of accuracy. The most accurate estimating

technique is bottom-up estimating.

What is bottom-up estimating?

Bottom-up is a cost estimating technique that involves estimating the cost of individual work

packages or schedule

activities with the lowest level of detail. The detailed cost is rolled up (or summarized) to higher

levels for total project

estimates. This summarized data is very useful for reporting and tracking purposes. Bottom-up

estimating provides a

higher degree of accuracy, provided the estimates at the work package level are accurate.

Answer options C, A, and B are incorrect. Parametric modeling and analogous estimating techniques

use top-down estimation model. These

are less accurate than the bottom-up estimation.

What is analogous estimating?

Analogous is an estimating technique that uses the values of parameter, such as scope, cost, budget,

and duration or

measures of scale such as size, weight, and complexity from a previous, similar activity as the basis

for estimation of the

same parameter for a future activity. It is a top-down estimating technique and is a form of expert

judgment. It provides a

lower degree of accuracy than other estimating techniques. This technique is primarily used when

there is a limited amount

of detailed information about the project or program.

What is parametric modeling?

Parametric modeling is an estimating technique that uses parameters, or project characteristics, to

forecast project costs.

It involves a top-down approach and is similar but more accurate than analogous estimating. It uses

historical data and

other variables to calculate an estimate for activity parameters, such as scope, cost, budget, and

duration.